Instead of looking for breeders, go look for a schutzhund club. That is where you'll find people with knowledge about the working line dogs in your area.
I used to go to a Schutzhund club in my area. They were the ones who told me about Varick's breeder. Another club member's dog is actually Varick's Uncle.
I believe he has his SchH2 title, though it may be 3 now. All the others had their GSDs imported. And some had Malinois, but that is too much dog for me. Lol.
Varick vom Haus Jeffery
Dark Sable, intact male
DDR/West German Show Lines